Sunday, April 3, 2011

How long will it take to clean up the Chernobyl mess and put it away?

The images of the nuclear power plants in Japan keep taking me back to Chernobyl.

This month is the 25th anniversary of the steam explosion at Chernobyl early in the morning of April 26, 1986. As the problems in Japan get worse, I wonder what will happen when CNN and the world go away, the Tokyo Electric Power Company is nationalized and we turn this over to the engineers and technocrats in Japan and in the world community.

The only real example we have is Chernobyl and a review of what has been done over the past twenty five years offers a grim picture of the years to come in Japan.

As part of the emergency response, the Soviet government hastily completed, in October of 1986, a steel and concrete structure that entombed the still hot pile. The pile contained 200 tons of material and close to a ton of radio-nuclides, unstable elements which emit powerful gamma rays for a long time. Most of the radio-nuclides at Chernobyl are plutonium, among the most dangerous materials that exist. Part of the Chernobyl plant’s mission was to supply the Soviet military with plutonium for nuclear weapons.

Around these materials are a crumbling sarcophagus, a legacy of abandoned communities, relentless expense, technical failure, amazing politics and a numbing inertia. My last post talked about Chernobyl’s heroism. This story is about the decades-long effort of trying to pick up Chernobyl and put it away.

According to the European Bank for Social Development, the administrator of a fund for stabilizing the Chernobyl site, the government of Ukraine, where the plant was located, was spending up to 5% of its Gross Domestic Product in the year 2000, 14 years after the incident, on the social, health and environmental consequences of the explosion. Next door neighbor Belarus, down wind, was spending even an even higher percentage of its wealth.

People

The plant operators' town of Pripyat, population 45,000, closed the day after the accident and people were evacuated. By the middle of May, a zone 18 miles wide was established that would relocate 116,000 people. In subsequent years, another 220,000 people were relocated and the exclusion zone extended from 1680 square miles to 2600.

In January, 2008, the Ukraine government announced a decommissioning plan that includes repopulating some of the contaminated areas. The government sees the regional economy as driven by agriculture and forestry. Initial infrastructure requirements will mean the refurbishment of gas, potable water and power systems. The burning of local wood will be banned and the eating of some wild foods, like mushrooms, strongly discouraged.

More than 21,000 homes would be connected to gas networks in the period 2011-2015 while another 5600 contaminated or broken down buildings are demolished. Over 1300 kilometres of road and ten new sewage works and 15 pumping stations are planned. The feasibility of agriculture will be examined in areas where the presence of caesium-137 and strontium-90 is low, "to acquire new knowledge in the fields of radiobiology and radioecology in order to clarify the principles of safe life in the contaminated territories," says the report.

The World Health Organization has estimated that 1,000 people suffered substantial radiation exposure and 4,000 people will eventually die as a result of cancers, mainly thyroid, caused by fallout, about the same number of people who die annually in China mining coal. Many people dispute the WHO estimates and the Internet is alive with a much more massive Chernobyl tragedy.

The Site

In the mid-90s, the international community began to pressure Ukraine to shut the three remaining units in the complex because of design flaws with the plants and concerns about the stability of the sarcophagus surrounding Unit Four. But closing the plants was a tough sell as they created half the electricity for the country. After the fall of the Soviet Union, a series of disputes with Russia over natural gas made it difficult to pursue natural gas plants as replacement power. Ukraine would build three new pressurized water reactors after its Independence.

Meantime, the RBMK (reaktor bolshoy moshchnosty kanalny) or high-power channel reactor, went through numerous upgrades of its safety technologies though the design still lacks a containment vessel, the part of the plant that saved the day at Three Mile Island. Today, 11 RBMK reactors are operating, all within the former Soviet Union. If current schedules are kept, the last four will be decommissioned in the 2020-2025 time frame.

As part of the negotiation, the international community committed to the decommissioning of the remaining reactors. That means stabilizing and storing the fuel rods of the now closed reactors, which have been sitting in their spent fuel pools for the better part of 15 years. The European Bank for Reconstruction and Development, working with money donated by several counties will supervise the decommissioning.

The rods are currently in water and other “wet” storage facilities, but will now be stored in dry cement casks, a technique called Dry Cask Storage. The fuel rod assemblies will be dried and disassembled before being put in the closed casks. Sixteen donors have contributed 320 million Euros specifically to this end. The contract to actually build and accomplish this task was signed last month. That’s right. Last month.

It was supposed to be done much earlier, but a contract let in 1999 to process the 25,000 fuel assemblies in the Chernobyl complex was cancelled in 2007 because technical difficulties emerged. Nearly all of the structures for this task were complete at the time of cancellation. The new contract calls for an interim spent fuel facility to be completed in 2014 with permanent facilities coming later.

If all goes well, the threat of Chernobyl to the world will be nearly over by 2017, though several activities will go on for the next 100-300 years. The vehicles for this accomplishment are called, in Europeonese, The New Self Confinement, which permanently entombs the remains of Plant Four and the Spent Fuel Storage Facility, the site where the spent fuel rods will be safely quarantined and where the structures will be disassembled and/or processed.

The remainder of the Chernobyl Safety Fund – nearly 700 million Euros – will turn the entire complex into an environmentally safe site. It will prevent water from intruding and dust, contaminated with Cesium, from dispersing. It will deconstruct the existing structure which will be laid down within the site or processed inside the New Safe Confinement.

The design contract was signed in 2007 and the driving of the pilings for the foundations of the two 50 ton capacity cranes started in 2010. Construction will start in 2012 and the facility will operate for 100 years.

I feel sad for the victims. I think two workers died right away on the night of the incident, and a further 28 people died within a few weeks as a result of acute radiation poisoning. This could have been prevented if the operators didn't turned off the safety systems. portable flare stacks